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Transport Properties of Ibuprofen Encapsulated in Cyclodextrin Nanosponge Hydrogels: A Proton HR-MAS NMR Spectroscopy Study
Published on: August 15, 2016
Effects of hydroxypropyl-beta-cyclodextrin on the chemical stability of a naphthoquinone in aqueous solutions
1Departamento de Farmacia, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina.
Abstract:
2-Hydroxy-N-(3,4-dimethyl-5-isoxazolyl)-1,4-naphthoquinone-4-imine (1), an antibacterial agent, was shown to form inclusion complexes with HP-beta-CD in aqueous solution. In the present work the kinetics of 1 degradation in aqueous buffer solution was investigated as a function of pH (2.34-3.95), HP-beta-CD concentration (0%-28% (w/v)) and temperature (60-90 degrees C). A second-order derivative spectroscopic methodology was developed for the kinetic investigations. The degradation showed to follow pseudo-first-order kinetics. Also, an specific acid catalysis was found and the introduction of up to 28% (w/v) HP-beta-CD to the reaction medium did not change this kinetic behaviour. The obtained results indicated that HP-beta-CD stabilises 1 against degradation in aqueous solutions.
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